VCP PLATING
Vertical Continuous Plating (VCP) is one of the best copper plating technologies in nowadays PCB manufacturing industry. VCP is completely defeat traditional copper plating for fabricating printed circuit boards, like HDI boards, Multilayer PCBs, Flexible circuits and Rigid-flex PCBs. With the development of electronic devices toward to multi-functionality and product minimization, electronic devices with multilayer circuit boards and HDI PCB boards have higher copper plating quality demand since the copper in the plated through holes (PTHs) and laser drilling microvias can assure reliability over the life of the electronic products. In past days, thicker copper plating demand was always the challenge in the PCB manufacturing industry. The horizontal copper plating technology cannot meet higher copper thickness in the holes for multilayer PCBs, but the Vertical Continuous Plating (VCP) can.
VCP technology is widely used for PCB manufacturing processes, such as panel plating, graphics plating, vias filling or half-filling holes plating, Flex PCB plating and etc. As a Rigid and flexible PCB supplier, we provide customers with Multilayer PCBs, HDI PCBs, Flexible PCBs, Rigid-flex PCBs and so on. Our PCB fabrication facility has been equipped with VCP line, which makes our manufacturing capabilities higher than other PCB manufacturers in China.
VCP Applications in PCB Production
- Conformal plating
- Blind Microvias (BMV) filling
- Thru-hole filling
- Pretreatment
- Metal Resist, electrolytic final finishes
How does VCP Work?
The VCP line uses the supercharged nozzle to spray up closely, and the high strength of liquid penetration ability, which can meet the demand of HDI PCB production. While traditional plating makes the potion into the hole only by soaking and swing. The strength is too small, and penetration ability is limited.
The Printed Circuit Boards of the high-end electronic products reply on state-of-the-art chipset, which increase in ball count, increase in number, and may also decrease in pitch. This increase in density generally drives layer counts higher (Multilayer), with pitch decrease leading to smaller holes, clearances, and trace widths and spacings. As layer count increases, board thickness increases. As the hole size decreases with pitch, the aspect ration (AR) increases, bringing with it a new set of challenges. Aspect ratio is defined as thickness/through hole diameter.
PCBs with high aspect ratio present many challenges, one of which is the ability to reliably plate the through holes without over-plating the surface layers. Typically, PCBs require 1mil (25.4 Microns) of copper in the hole. Ideally, we want the same amount of copper to be platted in the middle of the holes as on the surface. This presents a challenge due to electrochemical properties of plating processes combined with the aspect ratio of the PCBs being plated.
Throwing Power (TP) Percentage Determines the Copper Plating Result
TP percentage in VCP process defines the ratio of the copper plating thickness in the middle of hole compared to the plating thickness at the surface. Ideal TP% for a conformal plating process is in the 80%-120% range, and for manufacturing control it is best when the TP% has minimally variability dependence upon hole diameter.
